Poor service once again

Once again OK mini market in Athlone gave poor customer service. I must admit they have upped there game a bit where it comes to staff as the ones they have now are more friendlier. So today I walked into the store the specials were pasted on the door window as usual but I didn't bother to scrutinize it as they were advertised in store as well. I took two twizza cool drinks that was clearly marked on special on the fridge door. When I paid I noticed I had paid full price for the cooldrinks. I turned back and asked if the special is over and they said yes. The owner was standing there and I asked why are the specials still advertised if I am paying full price. He was abrupt and rude and said they didn't take off the notices and I must just give the cooldrink but for a refund. Seriously... Thats how u treat your loyal customers? Not even apologing or trying to convince me that it's an error on there side? That owner clearly needs to go on customer service course as he would not have liked to be treated like that if he had been the customer. This is my second bad experience at that specific store and I have been using that OK for many years. Previous owner was way better and actually cared for there customers.